55 lines
1.1 KiB
Go
55 lines
1.1 KiB
Go
// Go MySQL Driver - A MySQL-Driver for Go's database/sql package
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//
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// Copyright 2019 The Go-MySQL-Driver Authors. All rights reserved.
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this file,
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// You can obtain one at http://mozilla.org/MPL/2.0/.
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// +build linux darwin dragonfly freebsd netbsd openbsd solaris illumos
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package mysql
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import (
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"errors"
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"io"
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"net"
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"syscall"
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)
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var errUnexpectedRead = errors.New("unexpected read from socket")
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func connCheck(conn net.Conn) error {
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var sysErr error
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sysConn, ok := conn.(syscall.Conn)
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if !ok {
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return nil
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}
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rawConn, err := sysConn.SyscallConn()
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if err != nil {
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return err
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}
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err = rawConn.Read(func(fd uintptr) bool {
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var buf [1]byte
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n, err := syscall.Read(int(fd), buf[:])
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switch {
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case n == 0 && err == nil:
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sysErr = io.EOF
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case n > 0:
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sysErr = errUnexpectedRead
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case err == syscall.EAGAIN || err == syscall.EWOULDBLOCK:
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sysErr = nil
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default:
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sysErr = err
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}
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return true
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})
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if err != nil {
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return err
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}
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return sysErr
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}
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